Health and Wellness

Can face masks lower oxygen levels or weaken the immune system? Here's what health experts say

Meghan Holohan
Beachgoers wear face masks and walk dogs on the sand at Island Beach State Park in New Jersey, Saturday, May 2, 2020.
Wayne Parry | AP

Research has found that wearing a mask is one of the most effective methods Americans can take to slow the spread of the coronavirus.

Yet health myths about masks flood social media — people worry that wearing masks will lower oxygen levels or cause carbon dioxide poisoning. Others fear they'll develop bacterial infections from moist, sweaty masks or weaken their immune system's ability to fight off colds.

Health care professionals have attempted to clarify these misconceptions on social media. A doctor in South Carolina challenged the idea that "oxygen levels drop dramatically while wearing a mask." Dr. Megan Hall tested her oxygen saturation and heart rate using a pulse oximeter in four situations for five minutes at a time: One without a mask, one with a surgical mask, one with a N95 mask and one with a N95 and surgical mask.

"There is no significant change in my oxygen saturation (or HR) in any scenario. Though it maybe inconvenient for some, you can still breath," she shared on Facebook.

(TODAY reached out to Hall for an interview to discuss her popular post, but she declined.)

Debunking the myths

Wearing a mask remains incredibly safe and a good way to slow the spread of COVID-19. Masks work by filtering and suppressing air particles.

If someone's infected but doesn't have symptoms, what's known as asymptomatic, the particles from the mouth, nose and back of the throat come out when they breathe and spread out within about 6 feet. The mask stops some particles from spreading freely and pushes some air down instead of out.

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"Normal, healthy people can do quite energetic things while wearing the sorts of face coverings that we've been talking about in the context of COVID prevention," Dr. William Schaffner, an infectious disease professor at Vanderbilt University in Nashville and medical director of the National Foundation of Infectious Diseases, told TODAY. "If they were injurious, they couldn't be recommended by the CDC, state or local health departments."

Dr. Liam Sullivan, an infectious disease specialist at Spectrum Health in Grand Rapids, Michigan, said that if masks were dangerous, there'd be more cases of operating room nurses and doctors being ill.

"I don't see them dropping dead from lack of oxygen or too much carbon dioxide," he told TODAY.

Kirsten Koehler, an associate professor in environmental health and engineering at Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, who is an aerosol scientist, agreed.

"Scientific studies are showing that there's no real important changes in C02 levels or oxygen levels even from wearing surgical masks. And fabric masks have better permeation for gases," she told TODAY. "It's not something that I'm concerned about at all. Probably more likely is that people are hot when wearing a mask and so people maybe just feeling overheated."

Schaffner suspects that people worry about wearing masks because breathing feels difficult.

"If they wear masks correctly, it's true that the work of breathing is a little harder. But that just means that the mask is acting as a filter," Schaffner explained. "If you have to breathe in and it out of a filter, it takes a little more work."

Some say they can't wear a mask because of asthma or chronic obstructive pulmonary disease, though the experts suspect that many with compromised lung function are more willing to wear masks.

"The vast majority of the people with true underlying lung disease are going to wear a mask because they know if they get exposed to this virus, they're at very higher risk for serious complications," Sullivan said. "Sometimes when they're in a mask it can be a little difficult (to breathe)."

While wearing masks during warm weather might cause it to become damp with sweat, that shouldn't cause any bacterial infections.

"There's no evidence for that," Schaffner said. "If it's in the hot humid air of the summer, yes, it can get sweaty and yucky. If you have a cloth mask, you wash it. If you're wearing a surgical mask you have to use a new one."

Koehler recommends that people put moist cloth masks in paper bags to dry out (if swapping midday) and then wash them every day before using or wear a fresh disposable mask.

As for whether masks might compromise one's immune system, Schaffner said "that's malarkey."

Sullivan said that the immune systems work by immune memory, which occurs when the body encounters a bacteria or virus and responds. But masks don't prevent that from happening.

"I can pretty much guarantee to you that wearing a mask intermittently throughout the day or even all day long is not going to weaken your immune system," he said.

The real reason many people don't want to wear masks

The most common reason people don't want to wear a mask is because of psychological reasons. And the experts get it. Masks are awkward.

"It can be uncomfortable. I don't disagree with that," Sullivan said.

Koehler said that's actually why experts recommend social distancing and hand washing first.

"We put all masks under — what we call personal protective equipment — as the very last resort and that is because masks are, as I think most of us are recognizing now, really uncomfortable," she said.

And, people in Western countries just aren't familiar with wearing them. "It's obviously not the social norm," Schaffner said. It also has become a political issue and that makes some people less likely to wear them.

But the experts stress the virus doesn't care about politics. "Coronavirus is happy to infect everyone," Schaffner said.

Sullivan agrees. "The virus doesn't care about culture wars and it doesn't care about your freedom," he said. "Wearing a mask is about being a human being, about caring about your fellow human beings and respecting all human beings."

The article "Can Masks Lower Oxygen Levels? Experts Discuss Popular Myths About Masks" originally appeared on TODAY.

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